1. Field of the Invention
The present invention relates to a method of designing spokes of a non-pneumatic tire. More particularly, the present invention relates to a method of designing spokes of a non-pneumatic tire which randomly arranges spokes around a circumference of the tire to optimize noise dispersion.
2. Description of the Related Alt
Generally, a non-pneumatic tire includes spoke members which are arranged at regular intervals and at an angle in a certain range between inner and outer cylindrical members. The non-pneumatic tire has empty support spaces between the spoke members and the support spaces are discontinuously arranged by the spoke members, thereby causing substantial noise during driving of a vehicle.
For the non-pneumatic tire, although the spoke member serves an important role in view of supporting a vehicle, a spoke supporting load has a narrow area, so that impact to a tire contacting the road is entirely transmitted to an axle of the vehicle during driving of the vehicle.
In order to overcome such a disadvantage, non-pneumatic tires as shown in FIGS. 3 and 4 are conventionally suggested. A non-pneumatic tire of FIG. 3 has spokes 102 designed into two parts, wherein the number of spokes 102 on an outer circular spoke support 103a, which is in contact with a tread 101, is about two times more than the number of spokes on an inner circular spoke support 103b disposed inside the outer circular spoke support 103a. In this case, excitation frequency occurring by rotation of the tire can be doubled, while reducing the extent of force applied through the wad 101 by half.
A non-pneumatic tire of FIG. 4 also has spokes 102 designed into two parts, wherein the number of spokes 102 on an outer circular spoke support 103a and the number of spokes 102 on an inner circular spoke support s 103b are the same, but the spokes on the outer circular spoke support 103a are designed in three parts in a transverse direction, so that force imparted to the tire contacting the ground is dispersed in view of frequency.
These conventional non-pneumatic tires disperse impact by changing the number of spokes which contact the ground.